Coupled Lateral-Longitudinal Vehicle Dynamics Modeling to Predict the Loads Experienced by Side Gears in the Differentials

<div class="section abstract"><div class="htmlview paragraph">Lumped parameter vehicle dynamics models are generally used in early design and development of vehicles due to simplicity and computational efficiency. In the literature, these models are generally divided into longitudinal, lateral, and vertical dynamics. Most of these formulations are limited to bicycle models with the vehicle represented as a lumped mass but seldomly coupled lateral-longitudinal lumped parameter models are proposed. In this paper, a coupled lateral-longitudinal lumped parameter model is developed that can be used to investigate the loads (torque & speed) experienced by the side gears in the differential.</div><div class="htmlview paragraph">Side gears are connected to the left and right wheels through half shafts (axle shafts) and are in-mesh with pinion gears as part of a differential assembly. The differential experiences torque loading during all driving conditions but the pinion gear starts to rotate (mesh with side gears) when there is speed difference left to right (turning, split-mu, gravel, off-road etc.) A durability assessment of the side gears is generally performed using accelerated tests which involve high throttle, grade, gravel and turning maneuvers. In this study, the bicycle model is expanded to include all four wheels of the vehicle. Longitudinal and lateral weight transfer is considered. This type of model provides the ability to perform both lateral and longitudinal maneuvers of the vehicle along with different tire-road interactions for four wheels of the vehicle. Measured data is used to validate the model.</div></div>